Initial-starting unloader for air compressors



M. RIESNER Filed Aug. 27, 1926 2 Sheets-Sheet MICHAEL RIESNER.

INVENTOR ATTORNEY Dec.'24, 1929.

INITIAL STARTING UNLOADER FOR AIR COMPRESSORS Dec. 24, 1929. RIESNER 1,741,117

INITIAL STARTING UNLOADER FOR AIR COMPRESSORS Filed Aug. 27. 1926 2 Sheets-Sheet 2 MICHAEL RIESNER.

l VENTOR ATTORNEY Patented Dec. 24, 1929 MICHAEL RIESNER, OF CINCINNATI, OHIO, ASSIGNOR TO WORTHINGTON PUMP AND MACHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA INITIAL-STARTING UNLOADER FOR AIR COMPRESSGRS Application filed August 27, 1926.

This invention relates to air and gas compressors and more particularly to an automatic magnetic control for the unloading mechanism of the compressor.

The primary obj ectof the invention is the provision of a control mechanism used in connection with the starting and stopping of an electric driven air or gas compressor, which will unload the compressor when the operating current is shut off or while the compressor is operating at practically full speed and which will delay the loading of the com pressor, upon starting, until it has reached practically full speed.

In the present invention the unloading mechanism of the compressor is controlled by a governor valve which admits or cuts off flow of fluid under pressure in the unloading mechanism, and is operated by a solenoid energized by the last contactor on the current controller which makes connection at approximately 90% full speed. During opera tion, when the maximum air pressure has been reached the operating current is automatically shut off by a pressure regulator, the solenoid is de-energized, operates the governor valve for admitting fiuid under pressure to the unloading mechanism and unloads the compressor at the same instant that the operating current is shut OE. With a drop in receiver pressure the current is turned on by the pressure regulator, allowing the machine to start with the compressor in an unloaded condition. The operating motor is gradually brought to full speed, until at approximately 90% of full speed, contact is made, energizing the solenoid and operating the governor valve to relieve the unloading mechanism of the fluid under pressure; provision is made for the slow bleeding of the pressure fluid from the unloading mechanism to delay the loading operation thereof until the machine has reached full speed.

For the full understanding of the invention, a detailed description of constructions embodying the same in preferred form will now be given in connection with the accompanying drawings forming a part of this specification, and the features forming the Serial No. 131,852.

invention then specifically pointed out in the claims.

In the drawings Figure 1 is a diagrammatic view showing the improved loading and unloading mechanism in connection with the air and gas compressor.

Figure 2 is an enlarged section through the governor valve.

Flgure 3 is an enlarged section through a valve used in the mechanism.

Fi ure 4; is a diagrammatic view of a modified form of the unloading and loading mechanism showing it adapted for use in connection with high pressure compressors.

Figure 5 is an enlarged detail section of the governor valve used in the modified form.

Referring more particularly to the drawings, and with particular reference to Figures l to 3, an air compressor A of any approved type is illustrated, which has unloading mechanisms B associated therewith. The unloading mechanisms B may be of any approved type, preferably of the type illustrated and described in my prior Patent #1,:379J81.

In the present invention, the object is to automatically control the loading and unloading of the compressor A with the starting and stopping of the compressor, and to provide such loading and unloading, a piston valve structure 1 is provided which includes a cylinder 2 having a piston valve 3 slidably mounted therein. The piston valve 3 is provided with a reduced portion 4 to permit passage of I'iuid under pressure from the receiver 5 through the pipe 6, cylinder 2 and outwardly through the pipe 7 to the unloading mechanisms B. The piston 3 is connected by a suitable coupling 8 to a solenoid 9 of any approved construction. The solenoid 9 is electrically connected, one terminal to the lever contact 10 of the controller 11 which controls the operating current of the mechanism employed for operating the compressor A. The other pole of the solenoid 9 is connected to a contactor 12 positioned to be engaged by the controller lever 13 when the latter engages the last of the series of contactors 14; of the controller 11. The operation of the controller 11 which may be of any approved type now on the market, is in turn controlled by a pressure governor 15. The pressure governor 15 may be of any approved type such as manufactured by various electrical equipment manufacturers'and it is connected by a pipe 16 w1th the reservoir 5 for operating thegovernor 15 to control the stopping and starting of the compressor A through the controller 11.

The operation of the mechanism ust de scribed is as follows: Assuming that the compressor A is operating at full capacity; when the pressure in the receiver 5 reaches the maximum pressure for which the mechanism is set the pressure governor 15 will act to cut ofl the flow of energizing currentto the motor (not shown) used for operating the compressor A and when this current 18 cut off the solenoid 9 is de-energized. When the solenoid 9 is de-en'ergized the piston valve 3 drops and permits fluid under pressure to flow from the receiver-5 through the p pe 6, cylinder 2 and pipe 7 to the unloading mechanisms'B thereby unloading the compressor at substantially the same 1nstant in which the current is out off. If it is so desired the piston 4 may have a weight carrying rod 17 attached thereto on Wl11Cl1 any desired number of weights 18 may be mounted for'facilitating the dropping movement of the piston 3 and preventing the piston being forced upward by thepressure of fluid entering the cylinder 2.

Upon the drop in pressure in the receiver 5 the pressure governor 15 Wlll operate to turn on the "operating current through the controller 11 and as the controller 11 is of the approved type wherein the prime mover or motor is gradually brought to full speed, the solenoid 9 will not be energized until the lever 13 of the controller engages the contact 12' at which time the motor (not shown) and compressor A will be operating at substantially90%=of full speed. The controller '11 is of any approved form such as may be purchased on the open market and may be-either of the manual or automatic type --'as desired, a controller of the manually operated type being shown in the drawings.

-When the solenoid 9 is thus energized it will raise the piston 3 of the governor valve 1 cutting ofl communication between the pipes 6 and 7 and relieving the unloader mechanisms B of the fluid under pressure.

However, to prevent loading of the compres "sor A before it reaches full speed, a check anisms B. The fluid gradually bleeds from the'unload'er mechanisms B through the vent hole 21 in the disc 20 and out through the cylinder 2 to the atmosphere. The 'si'ze'of the vent hole 21 is regulated so that the unloading mechanisms B will be in loading position approximately at the same time as the compressor A reaches full speed.

, In Figures 4 and 5 of the drawings a modified form of the invention is shown which form is particularly adaptable for use in connection with high pressure compressing units and in general features of construction the modified form is similar'tothe preferred form above described in that it comprises in combination with multi-stage compressors C and D having unloading mechanisms E, a

governor valve 30 which is operated by the solenoid 31. The energizing and ole-energizing of the solenoid 31 is controlled by the controller 32 which, in turn,.-is operated by the pressure governor 33 which has connection through a pipe 34 with the receiver 35. In high pressure compressing units, such as compressing units above 250 pound pressure, it is necessary to reduce this pressure before applying it to the unloading mechanisms E and for this purpose a reducing valve 36 of any approved construction is positioned in the pipe line 37between the receiver 35 and the governor valve 30. A pop valve 38 is also shown for relieving pressure in the pipe line 37 prior to delivery of the fluid to the gover nor valve 30. V

The governor valve '30 is substantially of the same constructionas the governor valve 1, including a piston 40 which moves in the cylinder 41 for establishing or cutting off communication between the pipes 37 and the pipe 42. In the modified form, however, no weights similar to the weights 18 are illustrated. V

The operation of the modified form of the invention is the same as the operation of the preferred form above described in that the unloading mechanisms E are operated to unload the machine when the solenoid 31 energized, such operation being permitted by the dropping of the piston 40 while the raising of the piston 40 upon the energizing of the solenoid 41 cuts ofl flow of fluid under pressure tothe unloading mechanisms Eand permits such fluid as is in the unloading mechanisms to bleed to the atmosphere through the pipe 42 and the open end of the cylinder 41.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown but that these may be modified widely within the invention defined by the claims.

What is claimed is: I

1. The combination with an air or gas compressor, unloading mechanism therefor, and

the controller of-the prime mover of the com-- connected to said'piston for operating it to cut off flow of fluid to the unloading mechanism, said controller controlling energizing of said solenoid, the pressure fluid bleeding from said unloading mechanism through said governor valve to load the compressor upon operation of the piston by said solenoid, and means for retarding the bleeding of pressure fluid from said unloading mechanism to delay the loading of the compressor.

2. The combination with an air or gas compressor, and unloading mechanism therefor, and the controller of the prime mover of the compressor, of a governor valve includin a piston movable in one direction to cut 0% flow of operating fluid under pressure to said unloading mechanism, and movable in another direction to admit operating fluid under pressure to said unloading mechanism,

a solenoid connected to said piston for moving it to cut off the flow of fluid to the unloading mechanism, a counterweight connected to the piston to move it on de-energizing of the solenoid to permit the passage of pressure fluid to the unloader, said controller controlling energizing of said solenoid, a check valve between the piston and unloading mechanism provided with a bleed opening for retarding the bleeding of pressure from said unloading mechanism to delay the loading of the compressor.

In testimony whereof I aifix my signature- MICHAEL RIESNER. 

